Hodgkin's disease represents one of the major human malignancies, yet investigation of its biology has lagged far behind clinical studies. This is largely due to several unique aspects of Hodgkin's disease, including the fact that the neoplastic element, the Reed-Sternberg cells and variants, comprise a rare component of the cellular infiltrate, the difficulty to grow Reed-Sternberg cells in cell culture, and the phagocytic properties of Reed-Sternberg cells; all three of these features have made the study of Hodgkin's disease through standard molecular and immunologic techniques extremely difficult and relatively fruitless.It is proposed to utilize the technique of in situ hybridization to study Hodgkin's disease.Specific aims include the in situ identification and localization of Epstein-Barr viral genomes to a specific cell type in Hodgkin's disease tissues, in situ identification of cytokine mRNA in Hodgkin's disease tissues, in situ identification of oncogene mRNA in Reed-Sternberg cells of Hodgkin's disease tissues, and the in situ identification of immunoglobulin mRNA in Hodgkin's disease tissues, particularly in the "L&H" cells of the nodular lymphocyte predominant subtype. Protocols involving use of oligonucleotide probes on paraformaldehyde-fixed, frozen sections or formalin-fixed, paraffin-embedded sections will be primarily be utilized. In situ hybridization studies of the identification of Epstein-Barr viral genomes in Hodgkin's disease tissues will be initiated using cases known to be positive by slot blot hybridization studies (approximately 20% of cases of Hodgkin's disease), and will eventually be extended to other cases. In addition, polymerase chain reaction studies for EBV genome will also be performed. In situ hybridization studies of cytokine and oncogene mRNA will be performed on a variety of cases of typical Hodgkin's disease. Cytokine studies will include analysis of interleukin 1-6, tumor necrosis factor alpha and beta, and interferon alpha, beta, and gamma mRNA. The studies of oncogene expression will include a range of oncogenes known to be important in the pathogenesis of hematolymphoid and non-hematolymphoid tumors. Finally, cases of nodular lymphocyte predominant Hodgkin's disease will be studied by tissue in situ hybridization studies employing oligonucleotide probes or by the technique of in situ transcription in an attempt to identify light chain mRNA clonal restriction, evidence that would support the hypothesis of a relationship of nodular lymphocyte predominant Hodgkin's disease to B cell neoplasia.